Hair strengthening composition and method

ABSTRACT

A hair strengthening relaxing composition comprising a cationic polyquaternary polymer that is the product of a condensation reaction of a lower dialkylamine (C 1  -C 3 ), a difunctional epoxy compound and a third reactant selected from the group consisting of ammonia, primary amines, alkylene diamines having two to six carbon atoms, and polyamines; and a high-alkalinity hair relaxing agent.

TECHNICAL FIELD

This invention generally relates to strengthening hair. Moreparticularly, the invention relates to a composition and method forstrengthening hair that has been exposed to a relaxer.

BACKGROUND OF THE INVENTION

Human hair has a variety of textures, from fine to coarse and fromstraight to very curly. Hair is made of keratin which in turn is made ofpolypeptide chains bonded together by cystine (or disulfide) bonds,hydrogen bonds and salt linkages. The cortex is the inner part of thehair.

Curly hair is made of hair strands that have irregular surfaces thatmesh and tangle with each other to make combing more difficult. Amongindividuals with excessively curly hair, e.g., individuals of African orMiddle Eastern descent, it is especially popular to relax or straightenhair to increase hair manageability and ease of styling. The hair to berelaxed is either pressed or exposed to a relaxer that chemicallytransforms cystine bonds of the hair to lanthionine bonds. For thisreason, the term for the chemical relaxing process is lanthionization.

During chemical relaxing, the hair is wetted with the relaxer andrepeatedly smoothed and sometimes partially combed. Typical relaxerscontain an alkali metal hydroxide or guanidine hydroxide as an activeingredient. The relaxers greatly decrease the tensile strength of thehair making it more likely to break. Hair being relaxed that is stillwet loses as much as 45-50 percent (%) of the hair's original tensilestrength. Relaxed hair that is dry loses about 20-25% of the hair'soriginal tensile strength. It is presently theorized that the decreasein tensile strength is due to structural damage associated witha-helical deformation which occurs during relaxing.

The α-helical deformation of hair can occur under the followingconditions:

a) When the high alkalinity relaxers degrade cystine bonds of theα-keratin during straightening, partial deformation of the α-helixbecomes a reality which causes the loss of tensile strength in the hairfibers.

b) Partial deformation of α-helix could be caused by the mechanicalextension of hair fibers beyond yield and post-yield region which maynot be reversible, even when the fibers are allowed to relax, i.e., restin water.

c) During relaxing, degradation of cystine bonds and low level ofmechanical force applied while applying and smoothing relaxer cream onhair causes the deformation of α-helix in keratine fibers.

In chemical relaxing, once the desired degree of straightening isachieved, the relaxer is rinsed from the hair with water. The hair isthen cleansed using a low pH, acidic nondetangling shampoo which isknown as a neutralizing shampoo. After shampooing, the hair is veryraspy in nature and rough to the touch.

Conditioners are often applied to the hair after shampooing to softenthe hair. Quaternary ammonium compounds having chain lengths of about 11to about 18 carbon atoms are often a component of these conditioners.Unfortunately, most of these compounds do not work when exposed to therelaxer or shampoo, and, therefore, they can only be used inpost-shampooing conditioners. For example, U.S. Pat. Nos. 5,060,680 and5,148,822, both to Akhtar, disclose straightening hair by a method thatrequires removing substantially all of the relaxer from the hair priorto applying an aqueous hair texturing and strengthening composition tothe hair. Furthermore, these compounds do not strengthen hair whenincorporated into the relaxer.

It is, therefore, an object of the present invention to provide animproved hair strengthening composition and easy-to-use method forstrengthening hair.

SUMMARY OF THE INVENTION

The present invention provides an improved composition and method forstrengthening hair. The composition and method are particularly usefulfor strengthening human hair straightened by a high alkalinity relaxer.The present composition and method strengthen the hair even in thepresence of the relaxer.

According to the invention, a composition for treating hair includes ahair swelling component and a cationic polymer in an amount effective tostrengthen the hair. The hair swelling component is preferably the highalkalinity hair relaxer. The hair strengthening cationic polymer is awater-dispersible polyquaternary ammonium polymer that is the reactionproduct of a lower dialkylamine (C₁ -C₃), a difunctional epoxy-typereactant and a third reactant selected from the group consisting ofammonia, primary amines, alkylene diamines having two to six carbonatoms and polyamines.

The method includes the steps of applying a hair swelling component tohair in need of strengthening and applying the cationic polymer to hair.

It is presently theorized that the hair swelling component swells thehair to permit the cationic polymer to be affixed to the swollen hair,preferably to the hair cortex. The affixed cationic polymer remains onor in the hair even after the hair swelling component and cationicpolymer that is not affixed are removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A hair strengthening composition includes a hair swelling component anda cationic polymer.

The hair swelling component is capable of swelling the hair tofacilitate the cationic polymer to be affixed to the swollen hair. Apreferred hair swelling component is a high alkalinity hair relaxer thatcan have a pH in the range of about 11 to about 13.5.

The high alkalinity hair relaxer can be a multi-part hair relaxer systemor a single part hair relaxer. Multi-part relaxer systems having twoparts are known wherein the active hair relaxing ingredient, e.g.,guanidine hydroxide, is generated in situ by the combination of the twoparts. Typically, the multi-part relaxer system includes a cream relaxeras part A and a liquid activator as part B. Preferably, the cationicpolymer is a component of the cream relaxer. Also present in the creamrelaxer is one precomponent of the active hair relaxing ingredient. Apreferred precomponent is a hydroxide such as an alkaline earthhydroxide, e.g., calcium hydroxide. The liquid activator contains asecond precomponent of the active hair relaxing ingredient, such asthose disclosed in U.S. Pat. No. 4,314,572 to de la Guardia. The de laGuardia patent and all other patents, articles and the like referred toor otherwise identified in this specification are incorporated herein byreference in their entirety. A preferred second precomponent isguanidine carbonate. When parts A and B are mixed together, the calciumhydroxide and the guanidine carbonate react with the reaction productproduced being guanidine hydroxide, the active hair relaxing ingredient.The cream relaxer, Part A, may also include additional conventionalcomponents. The liquid activator, Part B, typically also includesdeionized water.

The single part hair relaxer preferably uses a hydroxide such as analkali metal hydroxide, e.g., sodium hydroxide, as the active hairrelaxing ingredient. The remaining components of the single part hairrelaxer are conventional.

The hair strengthening cationic polymer is described in more detail inU.S. Pat. No. Re. 28,808 to Panzer et al and U.S. Pat. No. 4,661,259 toWalterick et al. and is referred to in the '259 patent as a group (II)cationic polymer at column 3, lines 43 et seq. The cationic polymer is awater-dispersible polyquaternary polymer that is the reaction product ofa lower dialkylamine (C₁ -C₃), a difunctional epoxy-type reactant and athird reactant selected from the group consisting of ammonia, primaryamines, alkylenediamines having two to six carbon atoms and polyamines.

Representative epoxy-type reactants include epihalohydrins, e.g.,epichlorohydrin and epibromohydrin with epichlorohydrin being thepreferred epihalohydrin, diepoxides, e.g., 1,4-butanediol-diglycidylethers, and precursors of epihalohydrins and diepoxides, e.g.,1,3-dichloropropanol-2 and 1,4-dichloro-2,3-dihydroxybutane.

Representative polyamines include polyalkylpolyamines having thestructure disclosed in the '259 patent at column 3, lines 64 et seq.

The exact reaction parameters for the cationic polymer are specified inthe '808 reissue patent and need not be repeated herein.

The preferred cationic polymer is the reaction product of a secondaryamine and epihalohydrin in the presence of a small amount ofethylenediamine. See, for instance, EXAMPLE 2 of the '808 reissuepatent.

It is presently theorized that the preferred cationic polymer has thefollowing structure: ##STR1##

The molecular weight of the cationic polymer is in the range of about400×10³ to about 1×10⁶ with the molecular weight of the preferredcationic polymer being in the range of about 400-600×10³.

The cationic polymer in admixture with water is commercially availablefrom Betz Laboratories, Trevose, Pa. under the designation Betz polymer1195. The Betz polymer 1195 typically contains about 50 weight percent(wt%) of the cationic polymer and has an activity of about fiftypercent.

The hair swelling component is present in the hair strengtheningcomposition in an amount in the range of about 95 to about 99.5 wt %based upon the total weight of the hair strengthening composition. Thecationic polymer is present in an amount in the range of about 0.5 toabout 5 wt %.

The method of strengthening hair in need of strengthening includes thesteps of applying the hair swelling component to the hair and applyingthe cationic polymer. Preferably, the applying steps are performedsimultaneously. The hair is preferably contacted with the hair swellingcomponent for a time period sufficient to swell the hair. Some of thecationic polymer becomes affixed to the swollen hair. An aliquot of thecationic polymer can be affixed by penetrating the swollen hair,especially the cortex of the hair. The cationic polymer that is notaffixed can be removed as by rinsing the hair with water. The hairswelling component can also be removed, or can be neutralized, usingwater or a conventional neutralizer.

The following tests were used to determine the efficacy of the hairstrengthening composition containing a relaxer as the hair swellingcomponent and the cationic polymer on wet and dry hair fibers.

WET HAIR FIBERS

To determine the efficacy of the hair strengthening composition on wethair fibers, twelve inch long European dark brown hair, commerciallyavailable from DeMeo Brothers, New York is washed with a mild shampoocontaining 10% ammonium lauryl sulfate. The hair fibers are rinsed withtepid tap water for about two minutes and dried overnight at ambienttemperature, i.e., a temperature in the range of about 20° to about 30°C. Twenty-five shampooed fibers having approximately the same diameter,i.e. a diameter in the range of about 71 to about 80 microns, areselected and then each fiber is cut into two halves. The hair fiberswith the root end of the hair are identified as Group A, fibers 1-25,and are used as a control which is only treated with the relaxer. Thehair fibers having the tip end are identified as Group B, fibers 26-50,and are treated with either the strengthening composition containing therelaxer and the strengthening cationic polymer or the relaxer and acomparison, nonstrengthening cationic polymer. The root end of the hairfibers is known to be slightly stronger than the tip end because theroot end has had less exposure to damaging conditions. Therefore, onewould expect that the length of hair having the root end would have ahigher tensile strength than the hair fiber having the tip end. TheGroup A and B hair fibers are then immersed in tap water for at least 30minutes.

The initial work done to extend the hair fibers 20% of their originallength of 30 millimeters (mm) is conventionally referred to as an F20Index Study and is determined using a conventional Dia-Stron MTT underconditions well known to those skilled in the art. The value of theinitial work done to achieve 20% elongation is equal to X. The hairfibers of each group are then immersed in separate containers of waterand allowed to recover overnight in the water. After recovering, thehair fibers are mounted on separate rectangular processing slabs anddried at ambient temperature for 30 minutes before treatment with therelaxer (Group A) or treatment with the strengthening composition or therelaxer and comparison polymer (Group B) for 18 minutes. The hair fibersare rinsed with tepid tap water for three minutes, treated with dilutednonconditioning neutralizing shampoo for three minutes, rinsed withtepid tap water for one minute, unmounted and stored overnight in water.The hair fibers are then elongated 20% using the Dia-Stron MTT whilebeing periodically immersed in the water. Immersion is accomplished bymounting each end of a hair fiber sample into the holding clamps of aremote measurement jig for movement into and out of a water-filledcompartment. The value of the work done after treatment with the relaxerto achieve 20% elongation is equal to Y. The F20 Index is determinedusing the following Equation I:

    F20 Index=[(X-Y)/X]x100                                    I

DRY HAIR FIBERS

The above-described Group A and B hair fibers are equilibrated at 65%relative humidity and 21° C. overnight before determining the workrequired to extend them 20% of their original length. The initial workdone to achieve 20% elongation of the equilibrated hair fibers isdetermined using the Dia-Stron MTT at the above-described parameters.The value of the initial work done is equal to X. After testing, thehair fibers are immersed in water and allowed to recover overnight. Thehair fibers are then mounted by group on separate rectangular processingslabs and dried for 30 minutes at ambient temperature. The hair fibersare then treated with a relaxer (Group A) or with the strengtheningcomposition or the relaxer and comparison polymer (Group B) for 18minutes. The hair fibers are then rinsed with tepid tap water for threeminutes, treated with diluted nonconditioning neutralizing shampoo forthree minutes, rinsed with tepid tap water for one minute, unmounted,stored in water for one hour and transferred to an environmental room at65% relative humidity and 21° C. overnight. The dry hair fibers are thenelongated 20% using the Dia-Stron MTT at the above-described testparameters to determine the work done after treatment with the relaxer.The value of the work done after treatment is equal to Y. The F20 Indexis then determined using the above-described Equation I.

The relaxers, hair strengthening compositions and comparisonpolymer-containing relaxers used in the examples had the compositionsprovided in TABLES 1 and 2, below.

                  TABLE 1                                                         ______________________________________                                        Guanidine-Containing Relaxers                                                                    Hair      Merquat Polycare                                                    Strengthen-                                                                             100 -   133 -                                             Control   ing Com-  Containing                                                                            Containing                                        Relaxer   position  Relaxer Relaxer                                  Components                                                                             (Wt %)    (Wt %)    (Wt %)  (Wt %)                                   ______________________________________                                        PART A: Cream                                                                 Deionized                                                                              50.73         48.33     47.23     47.09                              Water                                                                         Propylene                                                                              2.00          2.00      2.00      2.00                               Glycol                                                                        Calcium  5.50          5.50      5.50      5.50                               Hydroxide                                                                     PEG-75          2.25        2.25      2.25      2.25                          Lanolin                                                                       Betz Polymer                                                                           --                 2.40      --        --                            1195 (50%)                                                                    Merquat 100                                                                            --                 --        3.00      --                            (40%)                                                                         Polycare 133                                                                           --                 --        --        3.64                          (33%)                                                                         Petrolatum                                                                             12.00         12.00     12.00     12.00                              Mineral Oil                                                                            18.00         18.00     18.00     18.00                              Fatty    8.00          8.00      8.00      8.00                               Alcohol                                                                       Ceteth-20                                                                              1.50          1.50      1.50      1.50                               Mazu DF         0.02        0.02      0.02      0.02                          200S                                                                          PART B: Liquid Activator                                                      Guanidine                                                                              25.00                                                                Carbonate                                                                     Deionized                                                                              75.00                                                                Water                                                                         ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        Sodium Hydroxide-Containing Relaxers                                                         Control    Hair Strengthening                                                 Relaxer    Composition                                         Ingredients    (Wt %)     (Wt %)                                              ______________________________________                                        Deionized Water                                                                              55.03          53.03                                           Propylene Glycol                                                                             2.00           2.00                                            Sodium Hydroxide (50%)                                                                       4.50           4.50                                            PEG-50 Lanolin         0.49           0.49                                    Betz Polymer 1195                                                                            --                     2.00                                    Petrolatum     12.00          12.00                                           Mineral Oil    17.00          17.00                                           Emulsifying Wax                                                                              10.00          10.00                                           Laneth-15      0.98           0.98                                            ______________________________________                                    

The following examples are given by way of illustration and notlimitation. In the following examples, if the coefficient of variance isconsiderably above 10, it is advisable to eliminate fibers withunusually low or high average work done to bring the coefficient ofvariance up to 10. Therefore, those fibers were eliminated to bring downthe coefficient of variance into the desirable range.

EXAMPLE I

DETERMINATION OF F20 INDEX FOR WET FIBERS TREATED WITH A GUANIDINERELAXER AND A HAIR STRENGTHENING COMPOSITION INCLUDING A GUANIDINERELAXER

The F20 Index was determined using the procedure described above underthe "WET HAIR FIBER" heading and the control guanidine relaxer and theBetz polymer 1195-containing hair strengthening composition of TABLE 1,above. The test results are provided in TABLES 3 and 4, below.

                  TABLE 3                                                         ______________________________________                                        Group A Wet Fibers: Control, Treated With                                     Guanidine Relaxer Without Cationic Polymer                                                                   F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         1      1.150       0.541      52.96                                           2      1.390       0.687      50.58                                           3      1.500       0.714      52.40                                           4      1.470       0.662      54.97                                           6      1.370       0.607      55.69                                           7      1.520       0.784      48.42                                           9      1.270       0.595      53.15                                          11      0.939       0.432      53.99                                          12      1.180       0.461      60.93                                          13      1.090       0.519      52.39                                          14      1.430       0.694      51.47                                          15      1.170       0.613      47.61                                          17      0.921       0.414      55.05                                          18      0.992       0.501      49.50                                          19      1.290       0.677      47.52                                          20      1.220       0.632      48.20                                          21      1.180       0.573      51.44                                          22      1.170       0.605      48.29                                          23      1.410       0.725      48.58                                          25      1.120       0.542      51.61                                          AVERAGE                51.74                                                  STANDARD DEVIATION (SAMPLE)                                                                           3.39                                                  COEFFICIENT OF VARIANCE                                                                               6.54                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                                  The standard deviation is for the sample of data.                             The coefficient of variance is determined by the following Equation II:       II. Coefficient of Variance = (Standard Deviation/Average) × 100   

                  TABLE 4                                                         ______________________________________                                        Group B Wet Fibers: Experimental, Treated With                                Guanidine Relaxer and Cationic Polymer Betz 1195                                                             F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        26      1.040       0.513      50.67                                          27      1.640       0.950      42.07                                          28      1.440       0.819      43.13                                          29      1.190       0.668      43.87                                          30      1.430       0.842      41.12                                          31      1.290       0.636      50.70                                          34      1.270       0.706      44.41                                          35      1.250       0.757      39.44                                          36      0.816       0.429      47.43                                          37      1.110       0.562      49.37                                          38      1.010       0.589      41.68                                          39      1.370       0.767      44.01                                          41      1.160       0.646      44.31                                          42      0.956       0.454      52.51                                          44      1.210       0.659      45.54                                          45      1.240       0.688      44.52                                          46      1.060       0.461      56.51                                          47      1.100       0.617      43.91                                          48      1.090       0.513      52.94                                          50      1.050       0.517      50.76                                          AVERAGE                46.44                                                  STANDARD DEVIATION (SAMPLE)                                                                           4.63                                                  COEFFICIENT OF VARIANCE                                                                               9.96                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 3 and 4, the average tensile strength losswas more than 11% less for the wet hair fibers treated with the hairstrengthening composition of the present invention as compared to thosetreated with the Control. This reduction in loss of tensile strengthmeans that the hair fibers are stronger and less prone to damage andbreakage as compared to hair treated with the Control.

EXAMPLE II

DETERMINATION OF F20 INDEX FOR DRY FIBERS TREATED WITH A GUANIDINERELAXER AND A HAIR STRENGTHENING COMPOSITION INCLUDING A GUANIDINERELAXER

The F20 Index was determined using the procedure described above underthe "DRY HAIR FIBER" heading and the control guanidine relaxer and theBetz polymer 1195-containing hair strengthening composition of TABLE 1,above. The test results are provided in TABLES 5 and 6, below.

                  TABLE 5                                                         ______________________________________                                        Group A Dry Fibers: Control, Treated With                                     Guanidine Relaxer Without Cationic Polymer                                                                   F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         1      2.570       1.910      25.68                                           3      1.950       1.510      22.56                                           5      2.640       1.980      25.00                                           6      2.890       2.240      22.49                                           9      2.830       2.140      24.38                                          15      1.970       1.470      25.38                                          16      2.860       2.060      27.97                                          17      3.190       2.360      26.02                                          18      1.970       1.460      25.89                                          19      3.030       2.350      22.44                                          23      1.750       1.340      23.43                                          AVERAGE                24.66                                                  STANDARD DEVIATION (SAMPLE)                                                                           1.78                                                  COEFFICIENT OF VARIANCE                                                                               7.21                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

                  TABLE 6                                                         ______________________________________                                        Group B Dry Fibers: Experimental, Treated With                                Guanidine Relaxer and Cationic Polymer Betz 1195                                                             F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        26      2.590       2.030      21.62                                          27      3.040       2.420      20.39                                          28      2.540       1.990      21.65                                          35      3.020       2.390      20.86                                          37      2.990       2.250      24.75                                          40      2.250       1.680      25.33                                          41      3.110       2.350      24.44                                          42      2.980       2.280      23.49                                          44      3.100       2.360      23.87                                          49      2.540       2.000      21.26                                          50      2.610       2.070      20.69                                          AVERAGE                22.58                                                  STANDARD DEVIATION (SAMPLE)                                                                           1.82                                                  COEFFICIENT OF VARIANCE                                                                               8.05                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 5 and 6, the average tensile strength losswas more than 9% less for the dry hair fibers treated with the hairstrengthening composition of the present invention as compared to thosetreated with the Control. This reduction in loss of tensile strengthmeans that the hair fibers are stronger and less prone to damage andbreakage as compared to hair treated with the Control.

EXAMPLE III

DETERMINATION OF F20 INDEX FOR WET FIBERS TREATED WITH A SODIUMHYDROXIDE RELAXER AND A HAIR STRENGTHENING COMPOSITION INCLUDING ASODIUM HYDROXIDE RELAXER

The F20 Index was determined using the procedure described above underthe "WET HAIR FIBER" heading and the control sodium hydroxide relaxerand the Betz polymer 1195-containing hair strengthening composition ofTABLE 2, above. The test results are provided in TABLES 7 and 8, below.

                  TABLE 7                                                         ______________________________________                                        Group A Wet Fibers: Control, Treated With                                     Sodium Hydroxide Relaxer Without Cationic Polymer                                                            F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         3      1.540       0.966      37.27                                           4      1.210       0.660      45.45                                           5      1.360       0.738      45.74                                           6      1.260       0.711      43.57                                           8      1.290       0.697      45.97                                          12      1.520       0.958      36.97                                          13      1.420       0.756      46.76                                          15      0.944       0.571      42.56                                          16      0.895       0.512      42.79                                          17      1.040       0.581      44.13                                          18      1.310       0.796      39.24                                          19      1.110       0.650      41.44                                          23      1.640       0.964      41.22                                          25      1.080       0.588      45.56                                          AVERAGE                42.76                                                  STANDARD DEVIATION (SAMPLE)                                                                           3.20                                                  COEFFICIENT OF VARIANCE                                                                               7.48                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

                  TABLE 8                                                         ______________________________________                                        Group B Wet Fibers: Experimental, Treated With                                Sodium Hydroxide Relaxer and Cationic Polymer Betz 1195                                                      F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        27      1.080       0.734      32.04                                          30      1.240       0.849      31.53                                          33      1.340       0.884      34.03                                          35      0.755       0.526      30.33                                          37      1.340       0.934      30.30                                          38      1.300       0.855      34.23                                          39      1.230       0.865      29.67                                          40      0.875       0.549      37.26                                          41      0.820       0.490      40.24                                          42      1.090       0.707      35.14                                          44      1.070       0.727      32.06                                          46      1.240       0.851      31.37                                          47      1.140       0.675      40.79                                          48      1.660       1.040      37.35                                          AVERAGE                34.02                                                  STANDARD DEVIATION (SAMPLE)                                                                           3.67                                                  COEFFICIENT OF VARIANCE                                                                              10.78                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 7 and 8, the average tensile strength losswas more than 25% less for the wet hair fibers treated with the hairstrengthening composition of the present invention as compared to thosetreated with the Control. This reduction in loss of tensile strengthmeans that the hair fibers are stronger and less prone to damage andbreakage as compared to hair treated with the Control.

EXAMPLE IV

DETERMINATION OF F20 INDEX FOR DRY FIBERS TREATED WITH A SODIUMHYDROXIDE RELAXER AND A HAIR STRENGTHENING COMPOSITION INCLUDING ASODIUM HYDROXIDE RELAXER

The F20 Index was determined using the procedure described above underthe "DRY HAIR FIBER" heading and the control sodium hydroxide relaxerand the Betz polymer 1195-containing hair strengthening composition ofTABLE 2, above. The test results are provided in TABLES 9 and 10, below.

                  TABLE 9                                                         ______________________________________                                        Group A Dry Fibers: Control, Treated With                                     Sodium Hydroxide Relaxer Without Cationic Polymer                                                            F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         2      3.170       2.540      19.87                                           3      2.250       1.840      18.22                                           4      2.230       1.780      20.18                                           6      2.300       1.910      16.96                                           8      2.950       2.340      20.68                                          10      2.440       1.950      20.08                                          12      2.490       2.010      19.28                                          18      2.790       2.320      16.85                                          19      2.190       1.790      18.26                                          20      2.870       2.230      22.30                                          21      2.400       1.830      23.75                                          22      3.130       2.390      23.64                                          25      2.880       2.250      21.88                                          AVERAGE                20.15                                                  STANDARD DEVIATION (SAMPLE)                                                                           2.28                                                  COEFFICIENT OF VARIANCE                                                                              11.30                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

                  TABLE 10                                                        ______________________________________                                        Group B Dry Fibers: Experimental, Treated With                                Sodium Hydroxide Relaxer and Cationic Polymer Betz 1195                                                      F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        26      2.410       1.950      19.09                                          28      2.780       2.200      20.86                                          29      2.350       1.900      19.15                                          33      3.120       2.600      16.67                                          35      2.380       1.970      17,23                                          36      3.410       2.750      19.35                                          38      2.910       2.310      20.62                                          41      2.640       2.140      18.94                                          45      2.870       2.390      16.72                                          46      2.290       1.940      15.28                                          47      2.920       2.470      15.41                                          48      3.170       2.660      16.09                                          49      2.950       2.430      17.63                                          AVERAGE                17.93                                                  STANDARD DEVIATION (SAMPLE)                                                                           1.87                                                  COEFFICIENT OF VARIANCE                                                                              10.45                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 9 and 10, the average tensile strength losswas more than 12% less for the dry hair fibers treated with the hairstrengthening composition of the present invention as compared to thosetreated with the Control. This reduction in loss of tensile strengthmeans that the hair fibers are stronger and less prone to damage andbreakage as compared to hair treated with the Control.

EXAMPLE V

DETERMINATION OF F20 INDEX FOR WET FIBERS TREATED WITH A GUANIDINERELAXER AND A MERQUAT 100-CONTAINING RELAXER

The F20 Index was determined using the procedure described above underthe "WET HAIR FIBER" heading and the Control guanidine relaxer and theMerquat 100-containing guanidine relaxer of TABLE 1, above.

The test results are provided in TABLES 11 and 12, below.

                  TABLE 11                                                        ______________________________________                                        Group A Wet Fibers: Control, Treated With                                     Guanidine Relaxer Without Cationic Polymer                                                                   F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         1      1.460       0.631      56.78                                           3      0.983       0.363      63.07                                           4      1.210       0.425      64.88                                           5      1.270       0.567      55.35                                           6      0.990       0.376      62.02                                           7      1.240       0.337      72.82                                           8      1.610       0.612      61.99                                           9      1.180       0.553      53.14                                          10      1.040       0.365      64.90                                          11      0.877       0.290      66.93                                          12      1.110       0.424      61.80                                          13      1.010       0.404      60.00                                          14      1.080       0.384      64.44                                          15      1.160       0.460      60.34                                          16      1.020       0.416      59.22                                          17      1.220       0.404      66.89                                          18      1.410       0.708      49.79                                          19      1.050       0.427      59.33                                          20      1.610       0.570      64.60                                          21      1.060       0.469      55.75                                          22      1.340       0.482      64.03                                          23      0.936       0.355      62.07                                          24      1.240       0.413      66.69                                          25      1.120       0.442      60.54                                          AVERAGE                61.56                                                  STANDARD DEVIATION (SAMPLE)                                                                           5.02                                                  COEFFICIENT OF VARIANCE                                                                               8.15                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

                  TABLE 12                                                        ______________________________________                                        Group B Wet Fibers: Experimental, Treated With                                Guanidine Relaxer and Cationic Polymer Merquat 100                                                           F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        26      1.420       0.582      59.01                                          27      1.020       0.423      58.53                                          28      0.998       0.349      65.03                                          29      1.180       0.382      67.63                                          30      1.130       0.487      56.90                                          31      0.884       0.291      67.08                                          32      1.550       0.538      65.29                                          33      1.070       0.460      57.01                                          34      1.080       0.347      67.87                                          35      0.711       0.212      70.18                                          36      1.160       0.384      66.90                                          37      0.819       0.338      58.73                                          38      1.020       0.357      65.00                                          39      1.400       0.477      65.93                                          40      0.923       0.384      58.40                                          41      1.260       0.384      69.52                                          42      1.380       0.626      54.64                                          43      0.982       0.360      63.34                                          44      1.650       0.590      64.24                                          45      1.100       0.447      59.36                                          46      1.370       0.529      61.39                                          47      0.987       0.275      72.14                                          48      1.250       0.359      71.28                                          49      1.360       0.412      69.71                                          AVERAGE                63.71                                                  STANDARD DEVIATION (SAMPLE)                                                                           5.09                                                  COEFFICIENT OF VARIANCE                                                                               7.98                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 11 and 12, the percent loss of tensilestrength is actually greater for the hair fibers treated with theMerquat 100-containing guanidine relaxer as compared to the hair fiberstreated with the Control guanidine relaxer. The Merquat 100 iscommercially available from Calgon Corporation, Pittsburgh, Pa. TheMerquat 100 is dially dimethyl ammonium chloride. Thus, the hair fiberstreated with the Merquat 100-containing relaxer are more likely to breakor be damaged than the hair fibers treated with the Control.

EXAMPLE VI

DETERMINATION OF F20 INDEX FOR WET FIBERS TREATED WITH A GUANIDINERELAXER AND A POLYCARE 133-CONTAINING RELAXER

The F20 Index was determined using the procedure described above underthe "WET HAIR FIBER" heading and the Control guanidine relaxer and thePolycare 133-containing guanidine relaxer of TABLE 1, above. ThePolycare 133 is commercially available from Rhone Poulene, Cranbury,Nev. The Polycare 133 is polymethylacrylamidopropyl trimunium chloride.

The test results are provided in TABLES 13 and 14, below.

                  TABLE 13                                                        ______________________________________                                        Group A Wet Fibers: Control, Treated With                                     Guanidine Relaxer Without Cationic Polymer                                                                   F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                         1      1.540       0.748      51.43                                           2      0.865       0.421      51.33                                           3      1.330       0.618      53.53                                           4      1.190       0.467      60.76                                           5      1.410       0.512      63.69                                           6      0.889       0.382      57.03                                           7      0.983       0.345      64.90                                           8      1.400       0.553      60.50                                           9      1.140       0.397      65.18                                          10      0.957       0.268      72.00                                          11      1.590       0.619      61.07                                          12      1.360       0.602      55.74                                          13      1.030       0.371      63.98                                          14      1.090       0.408      62.57                                          15      1.540       0.672      56.36                                          16      1.540       0.633      58.90                                          17      1.200       0.453      62.25                                          18      1.560       0.541      65.32                                          19      1.580       0.783      50.44                                          20      1.190       0.515      56.72                                          21      1.250       0.517      58.64                                          22      0.941       0.557      40.81                                          23      1.050       0.337      67.90                                          24      1.090       0.513      52.94                                          25      0.796       0.327      58.92                                          AVERAGE                58.92                                                  STANDARD DEVIATION (SAMPLE)                                                                           6.63                                                  COEFFICIENT OF VARIANCE                                                                              11.25                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

                  TABLE 14                                                        ______________________________________                                        Group B Wet Fibers: Experimental, Treated With                                Guanidine Relaxer and Cationic Polymer Polycare 133                                                          F20 Index After                                                    Work Done* Relaxer Treatment                                      Initial Work                                                                              After      (% Loss in                                     Fiber No.                                                                             Done* (X)   Relaxer (Y)                                                                              Tensile Strength)                              ______________________________________                                        26      1.440       0.672      53.33                                          27      1.000       0.479      52.10                                          28      1.310       0.582      55.57                                          29      1.200       0.397      66.92                                          30      1.390       0.484      65.18                                          31      1.010       0.408      59.60                                          32      0.987       0.317      67.88                                          33      1.610       0.652      59.50                                          34      1.170       0.468      60.00                                          35      0.964       0.266      72.41                                          36      1.590       0.604      62.01                                          37      1.320       0.517      60.83                                          38      0.972       0.337      65.33                                          39      1.240       0.439      64.60                                          40      1.600       0.623      61.06                                          41      1.680       0.778      53.69                                          42      1.050       0.342      67.43                                          43      1.440       0.515      64.24                                          44      1.510       0.670      55.63                                          45      1.350       0.502      62.81                                          46      1.200       0.400      66.67                                          47      1.320       0.524      60.30                                          48      0.969       0.279      71.21                                          49      1.240       0.574      53.71                                          50      0.793       0.302      61.92                                          AVERAGE                61.75                                                  STANDARD DEVIATION (SAMPLE)                                                                           5.71                                                  COEFFICIENT OF VARIANCE                                                                               9.24                                                  ______________________________________                                         *WORK DONE IS IN MILLIJOULES                                             

As can be seen from TABLES 13 and 14, the percent loss of tensilestrength is actually greater for the hair fibers treated with thePolycare 133--containing guanidine relaxer as compared to the hairfibers treated with the Control guanidine relaxer. Thus, the hair fiberstreated with the Polycare 133--containing relaxer are more likely tobreak or be damaged than the hair fibers treated with the Control.

It is presently theorized that the above-described advantages areachieved because the swelling of the hair fiber by the hair swellingcomponent permits the cationic polymer to be affixed to the hair. Thecationic polymer can be affixed by mechanical or chemical bonding to thehair. The swelling of the hair permits the cationic polymer to penetrateinto the cortex of the hair fiber and form an elastic network in thecortex. Even after the hair is rinsed, the polymer is locked inside thehair to increase the tensile strength of the hair fiber due to theelastic nature of the cationic polymer.

What is claimed is:
 1. A hair strengthening composition comprising:a. a hair-strengthening cationic polyquaternary polymer component comprising the product of a condensation reaction of a lower dialklylamine (C₁ -C₃), a difunctional epoxy compound and a third reactant selected from the group consisting of ammonia, primary amines, alkylene diamines having two to six carbon atoms, and polyamines; and b. A high alkalinity hair relaxer comprising at least one component selected from the group consisting of sodium hydroxide, guanidine hydroxide, alkali metal hydroxide and quaternary ammonium hydroxide:wherein said hair relaxer is present in an amount of about 95-99.5% and the cationic polyquaternary polymer component is present in an amount of about 5-0.5%, based on the total weight of said hair strengthening composition.
 2. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer comprises:a. a hydroxide; and b. a guanidine salt;wherein said hydroxide and said guanidine salt are combined to form guanidine hydroxide.
 3. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer comprises an alkali metal hydroxide.
 4. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer comprises at least one component selected from the group consisting of sodium hydroxide and guanidine hydroxide.
 5. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer is sodium hydroxide.
 6. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer has a pH of 11 to 13.5.
 7. The hair strengthening composition of claim 1 wherein said high-alkalinity hair relaxer is present in an amount sufficient to cause at least some relaxation of hair.
 8. The hair strengthening composition of claim 1 wherein said cationic polyquaternary polymer component comprises the product of a condensation reaction of ethylenediamine, dimethylamine and epichlorohydrin.
 9. The composition of claim 2 wherein the hydroxide comprises an alkaline earth hydroxide.
 10. The composition of claim 2 wherein the hydroxide is calcium hydroxide.
 11. The composition of claim 2 wherein the guanidine salt is guanidine carbonate.
 12. A hair strengthening composition comprising:a. an alkaline earth hydroxide; b. a hair strengthening cationic polyquaternary polymer component comprising the product of a condensation reaction of a lower dialklylamine (C₁ -C₃), a difunctional epoxy compound and a third reactant selected from the group consisting of ammonia, primary amines, alkylene diamines having two to six carbon atoms, and polyamines; and c. a guanidine salt;wherein said cationic polyquaternary polymer component is present in an amount of about 5-0.5%, based on the total-weight of said hair strengthening composition.
 13. The composition of claim 12 wherein the alkaline earth hydroxide is calcium hydroxide.
 14. The composition of claim 12 wherein the guanidine salt is guanidine carbonate.
 15. The hair strengthening composition of claim 12 wherein said cationic polyquaternary polymer component comprises a cationic quaternary polymer which is the condensation reaction product of a lower dialklylamine (C₁ -C₃), a difunctional epoxy compound and a third reactant selected from the group consisting of ammonia, primary amines, alkylene diamines having two to six carbon atoms, and polyamines.
 16. The hair strengthening composition of claim 12 wherein said cationic polyquaternary polymer component comprises the product of a condensation reaction of ethylenediamine, dimethylamine and epichlorohydrin.
 17. The composition of claim 12 wherein the hydroxide and the guanidine salt, when admixed, have a pH of 11 to 13.5.
 18. A hair strengthening composition comprising 95-99.5% total weight of a high alkalinity hair relaxer compound of pH 11 to 13.5 which comprises calcium hydroxide and guanidine carbonate; and 5-0.5% total weight of a component comprising a hair strengthening cationic polyquaternary polymer which is the product of a condensation reaction of ethylenediamine, dimethylamine and epichlorohydrin. 